There is known a conventional air conditioner having two refrigerant circuits, i.e., a primary refrigerant circuit and a secondary refrigerant circuit, as disclosed in Japanese Patent Application Laid-Open Gazette No. 62-238951. The primary refrigerant circuit is configured such that a compressor, a first heat source-side heat exchanger, a pressure reduction mechanism and a first user-side heat exchanger are connected in this order. The secondary refrigerant circuit is configured such that a pump, a second heat source-side heat exchanger and a second user-side heat exchanger are connected in this order.
Heat exchange is made between the first user-side heat exchanger of the primary refrigerant circuit and the second heat source-side heat exchanger of the secondary refrigerant circuit. The second user-side heat exchanger is placed in a room and air-conditions the room.